This invention relates in general to railway track sections and particularly to frogs, which are junctions where one rail crosses another.
A railway frog is employed where one track crosses another. For example, in a turnout, a switch will selectively switch a train from a main track to a turnout track. As the turnout track progresses in a curve from the switch, one of the rails, must cross a rail of the main track. The junction assembly at such crossing is called a frog. If two tracks cross each other, four frogs would be required, one at each intersection of one rail with another.
There are a number of different types of frogs. One type, referred to as a spring frog, has a fixed wing rail and a movable wing rail. The wing rails converge toward each other in a central area of the frog, then diverge from each other. A point member is located between the diverging portion of the wing rails. The point member has point rails on an end opposite the point that are joined to standard rails of the turn out and main track. A spring biases the movable rail against one side of the point member. The flange of a railcar wheel progressing from the main track onto the turnout enters between the movable rail and the point member, spreading them apart from each other. The tread of the wheel passes from the fixed wing rail onto the point. Similarly, when traversing from the turnout back onto the main track, the tread of the railcar wheel moves from the point onto the fixed wing rail.
In both cases, the tread crosses a gap between the point member and the fixed wing rail, this gap being provided for receiving wheel flanges of railcars that are passing through the frog on the main track. The gap increases the contact pressure of the wheel against the point and the fixed wing rail because the tread will not be fully supported on steel as it passes over the gap. This creates repetitive excessive loads on part of the fixed wing rail and point member that cause them to wear more than other portions of the frog. The point member is generally formed of austenitic manganese steel because of its ability to work harden under impact loads and its ability to be repaired by welding. The fixed wing rail of the spring frog can be made of conventional carbon steel as normally used in conventional rails, or the wing portion can be integral to the cast point of austenitic manganese steel. Once the wing portion wears to the point, it is not economical to repair, and the entire casting may be replaced. Replacing an entire casting is a time-consuming and expensive task. A rail made of austenitic manganese steel would be too expensive for the lengthy fixed wing rail.
In a bolted rigid frog, neither of the wing rails are movable. A flangeway is located on each side of the point member. Consequently, a gap must be traversed each time the tread of a railcar wheel passes between the point member and one of the wing rails. The wing rails of bolted rigid frogs are also formed with rails of conventional rail steel. Consequently, they also tend to wear in the areas that are contacted by the railcar wheel adjacent the point.
A railbound frog is rigid with a manganese wing integral to the point. The impact areas can be repaired to a certain point. However, every subsequent repair shortens the casting""s life, and replacement is costly.
The frog of this invention has an impact resistant insert located in at least one of the wing rails adjacent the point of the point member. The insert is preferably formed of austenitic manganese steel, but may be of other materials with similar properties. The insert may be cast, rolled or forged. The wing rail with the insert has a forward section with the head of the rail removed. The forward section has flanges on its lower end for mounting to a frog support. A web extends upward and has an upper edge. The insert has a head that is supported on the upper edge of the web. The insert also has a skirt that extends downward on one side. The skirt is bolted to the web and also preferably to the point member. In one embodiment, a base extends outward from the lower edge of the skirt. The base is bolted separately to the support member.
In the case of a spring frog, one of the inserts is utilized. That insert is located in the forward portion of the rigid wing rail adjacent the point of the point member. In the case of a bolted rigid frog, two of the inserts are utilized. Both inserts are located in the wing rails adjacent the point of the point member.